// ============== Formatting extensions ============================
// A common storage for all mode-specific formatting features
if (!CodeMirror.modeExtensions) CodeMirror.modeExtensions = {};

// Returns the extension of the editor's current mode
CodeMirror.defineExtension("getModeExt", function () {
    var mname = CodeMirror.resolveMode(this.getOption("mode")).name;
    var ext = CodeMirror.modeExtensions[mname];
    if (!ext) throw new Error("No extensions found for mode " + mname);
    return ext;
});

// If the current mode is 'htmlmixed', returns the extension of a mode located at
// the specified position (can be htmlmixed, css or javascript). Otherwise, simply
// returns the extension of the editor's current mode.
CodeMirror.defineExtension("getModeExtAtPos", function (pos) {
    var token = this.getTokenAt(pos);
    if (token && token.state && token.state.mode)
        return CodeMirror.modeExtensions[token.state.mode == "html" ? "htmlmixed" : token.state.mode];
    else
        return this.getModeExt();
});

// Comment/uncomment the specified range
CodeMirror.defineExtension("commentRange", function (isComment, from, to) {
    var curMode = this.getModeExtAtPos(this.getCursor());
    if (isComment) { // Comment range
        var commentedText = this.getRange(from, to);
        this.replaceRange(curMode.commentStart + this.getRange(from, to) + curMode.commentEnd
            , from, to);
        if (from.line == to.line && from.ch == to.ch) { // An empty comment inserted - put cursor inside
            this.setCursor(from.line, from.ch + curMode.commentStart.length);
        }
    }
    else { // Uncomment range
        var selText = this.getRange(from, to);
        var startIndex = selText.indexOf(curMode.commentStart);
        var endIndex = selText.lastIndexOf(curMode.commentEnd);
        if (startIndex > -1 && endIndex > -1 && endIndex > startIndex) {
            // Take string till comment start
            selText = selText.substr(0, startIndex)
                    // From comment start till comment end
                + selText.substring(startIndex + curMode.commentStart.length, endIndex)
                    // From comment end till string end
                + selText.substr(endIndex + curMode.commentEnd.length);
        }
        this.replaceRange(selText, from, to);
    }
});

// Applies automatic mode-aware indentation to the specified range
CodeMirror.defineExtension("autoIndentRange", function (from, to) {
    var cmInstance = this;
    this.operation(function () {
        for (var i = from.line; i <= to.line; i++) {
            cmInstance.indentLine(i, "smart");
        }
    });
});

// Applies automatic formatting to the specified range
CodeMirror.defineExtension("autoFormatRange", function (from, to) {
    var absStart = this.indexFromPos(from);
    var absEnd = this.indexFromPos(to);
    // Insert additional line breaks where necessary according to the
    // mode's syntax
    var res = this.getModeExt().autoFormatLineBreaks(this.getValue(), absStart, absEnd);
    var cmInstance = this;

    // Replace and auto-indent the range
    this.operation(function () {
        cmInstance.replaceRange(res, from, to);
        var startLine = cmInstance.posFromIndex(absStart).line;
        var endLine = cmInstance.posFromIndex(absStart + res.length).line;
        for (var i = startLine; i <= endLine; i++) {
            cmInstance.indentLine(i, "smart");
        }
    });
});

// Define extensions for a few modes

CodeMirror.modeExtensions["css"] = {
    commentStart: "/*",
    commentEnd: "*/",
    wordWrapChars: [";", "\\{", "\\}"],
    autoFormatLineBreaks: function (text) {
        return text.replace(new RegExp("(;|\\{|\\})([^\r\n])", "g"), "$1\n$2");
    }
};

CodeMirror.modeExtensions["javascript"] = {
    commentStart: "/*",
    commentEnd: "*/",
    wordWrapChars: [";", "\\{", "\\}"],

    getNonBreakableBlocks: function (text) {
        var nonBreakableRegexes = [
            new RegExp("for\\s*?\\(([\\s\\S]*?)\\)"),
            new RegExp("'([\\s\\S]*?)('|$)"),
            new RegExp("\"([\\s\\S]*?)(\"|$)"),
            new RegExp("//.*([\r\n]|$)")
        ];
        var nonBreakableBlocks = new Array();
        for (var i = 0; i < nonBreakableRegexes.length; i++) {
            var curPos = 0;
            while (curPos < text.length) {
                var m = text.substr(curPos).match(nonBreakableRegexes[i]);
                if (m != null) {
                    nonBreakableBlocks.push({
                        start: curPos + m.index,
                        end: curPos + m.index + m[0].length
                    });
                    curPos += m.index + Math.max(1, m[0].length);
                }
                else { // No more matches
                    break;
                }
            }
        }
        nonBreakableBlocks.sort(function (a, b) {
            return a.start - b.start;
        });

        return nonBreakableBlocks;
    },

    autoFormatLineBreaks: function (text) {
        var curPos = 0;
        var reLinesSplitter = new RegExp("(;|\\{|\\})([^\r\n])", "g");
        var nonBreakableBlocks = this.getNonBreakableBlocks(text);
        if (nonBreakableBlocks != null) {
            var res = "";
            for (var i = 0; i < nonBreakableBlocks.length; i++) {
                if (nonBreakableBlocks[i].start > curPos) { // Break lines till the block
                    res += text.substring(curPos, nonBreakableBlocks[i].start).replace(reLinesSplitter, "$1\n$2");
                    curPos = nonBreakableBlocks[i].start;
                }
                if (nonBreakableBlocks[i].start <= curPos
                    && nonBreakableBlocks[i].end >= curPos) { // Skip non-breakable block
                    res += text.substring(curPos, nonBreakableBlocks[i].end);
                    curPos = nonBreakableBlocks[i].end;
                }
            }
            if (curPos < text.length - 1) {
                res += text.substr(curPos).replace(reLinesSplitter, "$1\n$2");
            }
            return res;
        }
        else {
            return text.replace(reLinesSplitter, "$1\n$2");
        }
    }
};

CodeMirror.modeExtensions["xml"] = {
    commentStart: "<!--",
    commentEnd: "-->",
    wordWrapChars: [">"],

    autoFormatLineBreaks: function (text) {
        var lines = text.split("\n");
        var reProcessedPortion = new RegExp("(^\\s*?<|^[^<]*?)(.+)(>\\s*?$|[^>]*?$)");
        var reOpenBrackets = new RegExp("<", "g");
        var reCloseBrackets = new RegExp("(>)([^\r\n])", "g");
        for (var i = 0; i < lines.length; i++) {
            var mToProcess = lines[i].match(reProcessedPortion);
            if (mToProcess != null && mToProcess.length > 3) { // The line starts with whitespaces and ends with whitespaces
                lines[i] = mToProcess[1]
                    + mToProcess[2].replace(reOpenBrackets, "\n$&").replace(reCloseBrackets, "$1\n$2")
                    + mToProcess[3];
                continue;
            }
        }

        return lines.join("\n");
    }
};

CodeMirror.modeExtensions["htmlmixed"] = {
    commentStart: "<!--",
    commentEnd: "-->",
    wordWrapChars: [">", ";", "\\{", "\\}"],

    getModeInfos: function (text, absPos) {
        var modeInfos = new Array();
        modeInfos[0] =
        {
            pos: 0,
            modeExt: CodeMirror.modeExtensions["xml"],
            modeName: "xml"
        };

        var modeMatchers = new Array();
        modeMatchers[0] =
        {
            regex: new RegExp("<style[^>]*>([\\s\\S]*?)(</style[^>]*>|$)", "i"),
            modeExt: CodeMirror.modeExtensions["css"],
            modeName: "css"
        };
        modeMatchers[1] =
        {
            regex: new RegExp("<script[^>]*>([\\s\\S]*?)(</script[^>]*>|$)", "i"),
            modeExt: CodeMirror.modeExtensions["javascript"],
            modeName: "javascript"
        };

        var lastCharPos = (typeof (absPos) !== "undefined" ? absPos : text.length - 1);
        // Detect modes for the entire text
        for (var i = 0; i < modeMatchers.length; i++) {
            var curPos = 0;
            while (curPos <= lastCharPos) {
                var m = text.substr(curPos).match(modeMatchers[i].regex);
                if (m != null) {
                    if (m.length > 1 && m[1].length > 0) {
                        // Push block begin pos
                        var blockBegin = curPos + m.index + m[0].indexOf(m[1]);
                        modeInfos.push(
                            {
                                pos: blockBegin,
                                modeExt: modeMatchers[i].modeExt,
                                modeName: modeMatchers[i].modeName
                            });
                        // Push block end pos
                        modeInfos.push(
                            {
                                pos: blockBegin + m[1].length,
                                modeExt: modeInfos[0].modeExt,
                                modeName: modeInfos[0].modeName
                            });
                        curPos += m.index + m[0].length;
                        continue;
                    }
                    else {
                        curPos += m.index + Math.max(m[0].length, 1);
                    }
                }
                else { // No more matches
                    break;
                }
            }
        }
        // Sort mode infos
        modeInfos.sort(function sortModeInfo(a, b) {
            return a.pos - b.pos;
        });

        return modeInfos;
    },

    autoFormatLineBreaks: function (text, startPos, endPos) {
        var modeInfos = this.getModeInfos(text);
        var reBlockStartsWithNewline = new RegExp("^\\s*?\n");
        var reBlockEndsWithNewline = new RegExp("\n\\s*?$");
        var res = "";
        // Use modes info to break lines correspondingly
        if (modeInfos.length > 1) { // Deal with multi-mode text
            for (var i = 1; i <= modeInfos.length; i++) {
                var selStart = modeInfos[i - 1].pos;
                var selEnd = (i < modeInfos.length ? modeInfos[i].pos : endPos);

                if (selStart >= endPos) { // The block starts later than the needed fragment
                    break;
                }
                if (selStart < startPos) {
                    if (selEnd <= startPos) { // The block starts earlier than the needed fragment
                        continue;
                    }
                    selStart = startPos;
                }
                if (selEnd > endPos) {
                    selEnd = endPos;
                }
                var textPortion = text.substring(selStart, selEnd);
                if (modeInfos[i - 1].modeName != "xml") { // Starting a CSS or JavaScript block
                    if (!reBlockStartsWithNewline.test(textPortion)
                        && selStart > 0) { // The block does not start with a line break
                        textPortion = "\n" + textPortion;
                    }
                    if (!reBlockEndsWithNewline.test(textPortion)
                        && selEnd < text.length - 1) { // The block does not end with a line break
                        textPortion += "\n";
                    }
                }
                res += modeInfos[i - 1].modeExt.autoFormatLineBreaks(textPortion);
            }
        }
        else { // Single-mode text
            res = modeInfos[0].modeExt.autoFormatLineBreaks(text.substring(startPos, endPos));
        }

        return res;
    }
};
